基于不同分色原理的图像传感器类别及其应用特点

首先本文分析了以拜尔传感器为代表的滤色片阵传感器的分色原理和性能特点,介绍了基于像素插补的图像重建方式,然后介绍了无需像素重建的条形滤色片分色和利用硅晶体透射特性分色的两种图像传感器。最后介绍的是利用光学棱镜进行分色处理的3CCD及3CMOS传感器的主要性能特点。     

CCD传感器的跑偏检测应用研究

针对自动化生产流水线上的卷绕系统跑偏问题,介绍了一种基于线阵CCD传感器的跑偏检测系统。CCD图像传感器作为位置传感器来检测带材边缘位置量,将实时检测位置量与工艺设定的基准位置量相比较得出偏差,进而完成了带材跑偏的实时检测功能。     

水热处理对SnO2厚膜气敏传感器性能的影响

研完了水热处理对于SnO2厚膜气敏传感器性能的影响。为了便于作对比,首先把SnO2纳米粉（平均粒径约200nm）平均分为两份：一份不经处理,直接用传统的厚膜传感器制备工艺制成气敏传感器（称为“原粉传感器”）;另一份经过200℃水热处理后,用同样的工艺制备成厚膜气敏传感器（称为“预处理粉传感器”）。利用乙醇、丙酮、CH4、H2和CO气体对这两种气敏传感器的性能进行了测试,结果表明预处理粉传感器的灵敏度和选择性明显优于原粉传感器。为了分析出现这种差异的原因,我们对这两种传感器的显微结构进行了分析,并在此基础上对实验现象进行了讨论。     

CMOS 图像传感器的发展现状

目的　了解当前 CMOS图像传感器的发展状况 .方法　详细介绍了图像传感器的历史背景、发展现状、像素单元的结构、工作原理以及 CMOS图像传感器芯片的整体结构 ,并比较了 CMOS图像传感器和 CCD图像传感器的优、缺点 .结果　指出了 CMOS图像传感器发展趋势 .结论　 CMOS图像传感器具有美好的发展前途     

浅谈提高数码照相机成像质量的途径

影响数码照相机成像质量的因素有很多,本文在简单叙述了图像传感器传递图像信息过程后,从光学角度分析对数码照相机物镜的要求,提出了一种与图像传感器特点相适应的光学设计方法,提出对设计和制造过程中的杂光问题的探讨。     

基于数字图像识别和光纤传感器的直流大电流在线校准装置

在电解冶金和电化学工业领域,大量霍尔直流超大电流传感器无预留校准接口.针对这一实际问题,设计了一种基于数字图像识别和光纤电流传感器的直流大电流在线校准装置.该在线校准装置以光纤电流传感器为标准,利用图像传感器实时采集霍尔电流传感器二次显示仪表的示数图像,对采集到的图像进行灰度化、中值滤波、二值化、闭运算、字符分割等预处...     

图像配准方法研究

图像配准是图像处理的基本任务之一,常常是作为图像处理应用的前期处理步骤使用,用于将不同时间、不同传感器、不同视角下获取的两幅或多幅图像进行匹配。本文在对图像配准的几种变换介绍的基础上总结了现有的几种配准方法,并分别分析了其存在的优缺点,在文章结尾对图像配准的发展趋势做了展望。     

基于折射率变化的固化在线监测研究

先进复合材料的固化成型工艺十分复杂,目前在很大程度上仍依赖于经验工艺。为了实现复合材料固化工艺的透明化、科学化及智能化,提出了将光纤折射率传感器用于复合材料制造过程,研制了一种折射率光纤传感器,同时将光源、探测器、信号处理器等元器件集成化为一个便携式的光纤传感仪以利于生产现场使用。利用该传感器对常温固化树脂的固化过程进行了测量,将其与同等条件下迈克尔逊干涉仪对固化过程的监测结果进行了比较,二者具有良好的一致性。在实验室与生产现场两种条件下将光纤折射率传感器埋设于预浸料中对其固化工艺过程进行了监测。结果表明,该技术不仅可以用于新型树脂固化工艺制度的确定,也可用于复合材料固化工艺过程的在线监测。     

应变式称重传感器技术现状及创新发展趋势(待续)

根据近些年来国内外应变式称重传感器结构设计与计算、制造工艺与工艺装备、计量性能检测等技术进步与新产品和自主知识产权产品研发情况,介绍了国际、国内应变式称重传感器技术发展现状。在分析国际应变式称重传感器发展潮流和战略前沿技术的基础上,介绍了结构设计、制造工艺、具体应用方面的创新发展概况和面对新需求的转型发展趋势,并提出了当前预先研究、产品开发与扩大应用方面的研究课题。     

应变式称重传感器技术现状及创新发展趋势(续完)

根据近些年来国内外应变式称重传感器结构设计与计算、制造工艺与工艺装备、计量性能检测等技术进步与新产品和自主知识产权产品研发情况,介绍了国际、国内应变式称重传感器技术发展现状。在分析国际应变式称重传感器发展潮流和战略前沿技术的基础上,介绍了结构设计、制造工艺、具体应用方面的创新发展概况和面对新需求的转型发展趋势,并提出了当前预先研究、产品开发与扩大应用方面的研究课题。     

State-of-the-art and recent developments in micro/nanoscale pressure sensors for smart wearable devices and health monitoring systems

Small-sized, low-cost, and high-sensitivity sensors are required for pressure-sensing applications because of their critical role in consumer electronics, automotive applications, and industrial environments. Thus, micro/nanoscale pressure sensors based on micro/nanofabrication and micro/nanoelectromechanical system technologies have emerged as a promising class of pressure sensors on account of their remarkable miniaturization and performance. These sensors have recently been developed to feature multifunctionality and applicability to novel scenarios, such as smart wearable devices and health monitoring systems. In this review, we summarize the major sensing principles used in micro/nanoscale pressure sensors and discuss recent progress in the development of four major categories of these sensors, namely, novel material-based, flexible, implantable, and selfpowered pressure sensors.     

Direct and chemically-mediated absorption spectroscopy usingoptical fiber instrumentation

This paper shows various applications of optical fiber sensors to absorption spectroscopy. Sensors for the monitoring of chromium in sewage water and for the colorimetry of gasoline samples are presented together with sensors for radiation dosimetry in radiotherapy and for lighting control in museum environments. In all these sensors, a combination of broadband and multi-band spectral measurements are collected using the same custom instrumentation unit consisting of LED light sources and an optical fiber microspectrometer. Extensions of the unit to implement other sensors making use of visible spectral range are discussed. The custom instrumentation implemented to address these sensors is their key unifying feature. It opens the possibility of addressing other sensors making use of absorption-based optrodes which present an analyte-modulated absorption spectrum in the visible spectral range     

Optimization of gas-sensitive polymer arrays using combinations of heterogeneous and homogeneous subarrays

Results for optimizing an array of conducting polymer gas sensors for sensing one of five analytes in the presence of up to four interferents are presented. The optimized array consists of subarrays of homogeneous (like) sensors contributing to a larger heterogeneous array of up to ten points (unlike sensors) in multidimensional sensor space. The optimization techniques presented here are linear, since the polymer sensors in their useful (low concentration) operating range exhibit linear and additive response characteristics. The optimization of these arrays produces maximum separability between analytes, demonstrating the trade-off between the addition of both information and variability induced by increasing the size of the heterogeneous array. Optimization results for sensing acetone, hexane, THF, toluene, and ethanol in the presence of interferents result in array sizes that are significantly less than the maximum available number of sensors (ten in the heterogeneous partition of the array). This result adds fuel to the argument that fewer sensors are better; the argument for more sensors, however, is also made in the context of the electronic nose systems where significant chemical diversity is required. Homogeneous subarrays of up to four elements each improve the separability of analytes in these optimized heterogeneous arrays by over 10% and also effectively flag broken or unhealthy sensors in a manner that is independent of analyte and concentration.     

Nanomaterials in Smart Packaging Applications: A Review

Food wastage is a critical and world-wide issue resulting from an excess of food supply, poor food storage, poor marketing, and unstable markets. Since food quality depends on consumer standards, it becomes necessary to monitor the quality to ensure it meets those standards. Embedding sensors with active nanomaterials in food packaging enables customers to monitor the quality of their food in real-time. Though there are many different sensors that can monitor food quality and safety, pH sensors and time-temperature indicators (TTIs) are the most critical metrics in indicating quality. This review showcases some of the recent progress, their importance, preconditions, and the various future needs of pH sensors and TTIs in food packaging for smart sensors in food packaging applications. In discussing these topics, this review includes the materials used to make these sensors, which vary from polymers, metals, metal-oxides, carbon-based materials; and their modes of fabrication, ranging from thin or thick film deposition methods, solution-based chemistry, and electrodeposition. By discussing the use of these materials, novel fabrication process, and problems for the two sensors, this review offers solutions to a brighter future for the use of nanomaterials for pH indicator and TTIs in food packaging applications.     

Microfluidic-assisted assembly of fluorescent self-healing gel particles toward dual-signal sensors

Journal of Materials Science - Quantum dots (QDs)/gel composites have sparked tremendous interests due to their great potentials in sensors. However, in most cases, these sensors are focused on...     

GaN and InN nanocolumns as electrochemical sensing elements: Potentiometric response to KCl, pH and urea

GaN and InN nanocolumns have been explored as electrochemical sensing elements. It is shown that these nanostructured sensors respond to anions as their corresponding compact crystals, but with a much lower sensitivity (chloride anion detection). Moreover, even though both kinds of nanocolumns are found to be more vulnerable to HCl etching compared to their flat counterparts, they exhibit quite high pH sensitivity. This fact allows for their use as pH sensors only under mild conditions, such as in biosensing systems, as it is proved with the example of urea biosensors.     

Improvement in sensitivity and selectivity of InP-based gas sensors: pseudo-Schottky diodes with palladium metallizations

The possibility of using single resistive n-type InP semiconductor gas sensors to perform accurate measurements of ozone or nitrogen dioxide concentration in air comes up against their low sensitivity and the inability to discriminate between the influence of each gas on the sensors without any exterior apparatus. To improve these two fundamental aspects of gas sensors, the sensitive n-InP layers have been included in more complex devices, called pseudo-Schottky diodes. Made by successive evaporation of metallic thin layers on p-InP substrates, their Schottky metallization schemes (Pd/Ge/Pd) satisfy a double objective: the creation of the necessary n-InP gas sensitive layer by activation of Ge dopants and the ozone catalytic conversion by palladium layers. Comparisons between the sensing performances of the two gas sensors (resistive and Schottky diode-type ones) show that sensitivity of the laters is largely higher than that of single resistive gas sensors. On the other hand, a good selectivity toward ozone is achieved with Pd/Ge/Pd/p-InP gas sensors, resulting from different reaction kinetics between O/sub 3/ or NO/sub 2/ and the sensitive layer. These differences can be attributed to the palladium metallization catalytic activity.     

Performance evaluation of algorithms for SAW-based temperature measurement

Whenever harsh environmental conditions such as high temperatures, accelerations, radiation, etc., prohibit usage of standard temperature sensors, surface acoustic wave-based temperature sensors are the first choice for highly reliable wireless temperature measurement. Interrogation of these sensors is often based on frequency modulated or frequency stepped continuous wave-based radars (FMCW/FSCW). We investigate known algorithms regarding their achievable temperature accuracy and their applicability in practice. Furthermore, some general rules of thumb for FMCW/FSCW radar-based range estimation by means of the Cramer-Rao lower bound (CRLB) for frequency and phase estimation are provided. The theoretical results are verified on both simulated and measured data.     

Fiber Bragg grating displacement sensor for movement measurement of tendons and ligaments

Biomechanical studies often involve measurements of the strains developed in tendons or ligaments in posture or locomotion. Fiber-optic sensors present an attractive option for the measurement of strains in tendons and ligaments because of their low cost, ease of implementation, and increased accuracy compared with other implantable transducers. A new displacement sensor based on a fiber Bragg grating and shape memory alloy technology is proposed for the monitoring of tendon and ligament strains in different postures and in locomotion. After sensor calibration in the laboratory, a comparison of the fiber sensors and traditional camera displacement sensors was carried out to evaluate the performance of the fiber sensor during the application of tension to the Achilles tendon. Additional experiments were performed in cadaver knees to assess the suitability of these fiber sensors to measure ligament deformation in a variety of simulated postures. The results demonstrate that the proposed fiber Bragg grating sensor is a highly accurate, easily implantable, and minimally invasive method of measuring tendon and ligament displacement.     

FDA Regulation of Implantable Sensors: Demonstrating Safety and Effectiveness for Marketing in the U.S.

Implantable sensors are gaining considerable attention in the research and medical communities due to their potential to enhance the detection and monitoring of medical conditions such as cancer, diabetes, and heart disease. The use of implantable sensors for these exciting applications bring them under the regulatory oversight of the United States Food and Drug Administration (FDA). As medical devices intended for long-term implantation that inherently involve some risk, the FDA will carefully evaluate these products prior to allowing them to enter the U.S. market. This paper provides a brief overview of the FDA medical device regulatory framework under which implantable sensors for medical purposes are regulated. It also addresses particular concerns the FDA may raise with respect to these products including, potential sensor breakage and migration in vivo, biocompatibility, electromagnetic compatibility, electromagnetic interference, wireless telemetry, risk/benefit, and clinical utility.